Same issue with my oculus. When it happen, I removed it and wait 10 - 20 sec than replaced it on my head. Usually it fix the issue for the rest of the flight, but sometime I have to repeated it.
Just clear the axes in red than click on default for each one. If the default is not the one you are using, re-map it. Close DCS and this should be good. It's what I did on my side.
Just delete the export.lua file in your script folder. Doing this resolved all the problem we had with Tars. The file will be re-create as soon you will restart DCS.